Sealing machine



Dec. 23, 1947. J. N. VAN EPPS ET AL SEALING MACHINE Filed Oct. 18, 19443 Sheets-Sheet 1 1 2 0/12 Join: M Van]? 7072n WJzra 1947. J. N. VAN EPPsET AL 2,433,176

SEALING MACHINE Filed Oct. 18, 1944 3 Sheets-Sheet 2 I"? jg", 2.

John /V. Van Z'pps. film Whnws.

Patented Dec. 23, 1947 SEALING MACHINE John N. Van Epps, ClevelandHeights, and John W. Kraus and Frank Ma gyar, Cleveland, Ohio,

assignors to Thompson Products, Inc., Cleveland, Ohio, a corporation ofOhio Application October 18, 1944, Serial No. 559,188

6 Claims. (01. 154-42) Our invention relates to the sealing ofcontainers or packages, and particularly to the sealing of containerssuch as bags which contain material to be protected or form part ofpackage or container assemblies in which. the-material or goods iscontained. Bags for this purpose must be of air-tight and moistureandvapor-proof material, and where the goods to be protected are of metalcoated with grease or other substance, the material of the bags must beproof against grease or such other substance. Bags of pliofilm are beingused quite extensively for sealed packaging but our invention would beapplicable for sealing bags of other material, such as paper, metallicor textile material impregnated or coated with protective substancessuch as waxes, thermoplastics, or other suitable substances.

An important object of our invention is to produce a simple, efficientsealing machine for sealing the mouths of bags after they have receivedthe contents to be protected or after packages with which the sealingbags are associated, have been assembled.

A further object is to provide a sealing machine having jaws betweenwhich the closed mouth of a bag may be inserted for clamping by the jawsand heating of the sealing substance in the bag material, and pressureclamping together of the bag walls along a sealing zone for closure ofthe bag mouth.

A further object is to provide electrical means for producing thesealing heat, and power means for controlling the closure of the sealingjaws,

together with means for automatically controlling the operation of theheating and clamping means when a container or package is brought intoproper position for sealing of the bag.

A further object is to provide electrical control means for the heatingmeans and the power clamping means with the circuits for said electricalcontrolling means automatically controlled by a switch which is actuatedwhen a package and sealing bag therefor are moved into sealing position.

Another object is to provide time controlled means for automaticallycontrolling the circuits for release of the clamping jaws from the bagafter a predetermined period of heat application to a bag along thesealing line.

A further object is to produce an adjustable thermo sealing machine forsealing the mouths, openings or seams of various sizes or shapes of bagsor containers, or package assemblies which include sealing bags.

The above referred to and other features of our invention are embodiedin the structure shown on the drawings, in which drawings.

. Figure 1 is a side elevation of the machine showing the sealing of abag thereby;

Figure 2 is a front elevation of the machine;

Figure 3 is a plan view of the heating and clamping jaw structureshowing the movable Jaw in open position;

Figure 4 is an enlarged section on plane IV-IV of Figure 2; and

Figure 5 is an enlarged section showing more clearly the clamping of thebag mouth during heat application thereto.

The machine shown comprises the supporting plate or table Ill on which asupporting block ll ismounted and secured as by screws i2. Mounted onthis block by screws I3 is a vertical rectangular guide frame l4 havingopposed parallel vertically extending guide walls I5 with guide ways l6thereon for a carrier head H. The head I! is vertically adjustable inthe frame M by means of a screw shaft l8. The screw shaft at its lowerend extends into a socket I 9 formed on the top of the head I! and theshaft is held against rotation relative to the head by a pin 20.

The screw shaft receives a take-up nut structure 2| comprising a shank22 extending through an aperture 23 in the top wall 24 which spans theupper ends of the guide walls 15 of the guide frame 2i. The shankterminates at its lower end in a flange 25 and at its upper end in apolygonal head 26 for receiving a wrench or other tool. Below the headthe shank has arms 21 extending therefrom provided with holes 28 inwhich rods or other tools may be inserted for turning of the nutstructure. The flange 25 and the arms 21 form stops for holding the nutstructure against axial movement. Upon turning of the nut structure thescrew shaft will be axially shifted for vertical adjustment of the headl'l in the guide frame H.

The carrier head H has the bore 29 therethrough for receiving a hollowor tubular arm 30. The head and the arm have opposed keyways forreceiving a key 3| which holds the arm 30 against rotation in the headl'l but permits axial adjustment of the arm in the head. A set screw 32is provided for locking the arm in adjusted position.

At its outer end the arm 30 has the transverse slot 33 in its upper sidein which is seated a supporting structure of right angular cross-sectioncomprising the vertical back plate 34 in the rear end of the slot andthe horizontal plate 35 seated in the bottom of the slot. These twoplates are rigidly secured to the arm 30, as by welding. A heater frameof right angular cross-section is supported by the plates 34 and 35 andcomprises the vertical wall 36 engaging against the front of the plate34, and the horizontal wall 31 seating on the plate 35. As shown onFigures 2 and 3, the heater frame extends laterally in horizontaldirection beyond the supporting plates 34 and 35 and is secured in placeby attachment of its wall 38 to the plate 34. Referring to Figure 1,threaded studs 38 are butt welded to the wall 38 to extend therefromthrough holes 39 in the plate 34 to receive lock washers and nuts 40.

The base wall 31 of the heater frame extends a distance forwardly beyondthe supporting plate 35 and has the upstanding flange or heating head 4|along whose outer side extends the heating nose or boss 42 whose frontsurface is in a vertical plane. In the corner between the wall 31 andits flange 4| extend electrical heating coils 43 from which heat isconducted to the heating head. The heating frame is closed at its endsby end walls 44 and 45, in order to maintain the temperature within theheater frame and avoid loss of heat, and a sheet metal cover 46 may beprovided for the frame.

Saddled on the arm 30 rearwardly of the heater structure is a bracketblock 41 secured to the arm as by welding and having the arm 48extending forwardly therefrom across the top of the heater structure,side walls 49 and 50 extending up from the block and the arm andprojecting forwardly beyond the heater structure. Extending downwardlybetween the front ends of the side walls 49 and 58 is a jaw bar 5| whichis fulcrumed near its upper end by the pin 52 extending through the sidewalls. At its lower end this jaw bar has a transversely extendingrectangular slot 53 in its rear side. In the inner end of the slot is abacking or spacer bar 54, and in the forward end of the slot is apressure blade structure 55. This blade structure comprises a channelbar 58 in which is inserted a strip 51 of resilient material having thecharacteristics of rubber. A hard rubber or similar material face 58 isvulcanized to the outer face of the resilient strip 51. The bar 5| isfulcrumed to be swung down to bring the blade structure with its faceplate 58 into parellelism with the flat face of the heating boss 42 toengage the mouth end of a bag inserted between the blade structure andthe heating boss to be sealed.

Describing now the mechanism for operating the jaw bar 5|, a supportingblock 59 saddles n the arm 30 rearwardly of the block 41 and is securedto the arm as by welding. Mounted on the block 59 is a cylinder 68having a piston 6| therein from which the piston rod 8| extendsforwardly through the cylinder head. A connecting rod 62 has the fiatouter end 63 engaging in a slot 64 in the upper end of the jaw bar towhich it is pivoted by the pin 65. At its rear end the connecting bar isthreaded to receive a clevis 88 which is pivotally connected to theouter end of the piston rod as indicated at 61. A plate 68 extendsbetween and is secured to the rear ends of the side walls 49 and 58 andhas the opening 89 therethrough from which the connecting rod extends.An abutment washer is adjustable axially on the connecting rod by meansof nuts 1| engaging the threaded end of the rod, and a compressionspring 12 encircles the rod and abuts the plate 68 and the washer 10,this spring being used for adjusting the pressure between the twosealing jaws and tending to shift the connect- 4 ing bar rearwardly forupward swing of the jaw bar 5|, as indicated by the dotted lines onFigure 4.

The cylinder is connected to receive air under pressure through a pipe13, this air pressure shifting the piston outwardly against theresistance of the spring 12 to swing the jaw bar 5| down into sealingposition, as shown on Figure 1, and by full lines on Figure 4. As shownon Figure 2, the air flow to the cylinder is controlled by a rotaryvalve V which when open connects the pipe 13 with the air supply pipe14. Figure 2 shows the valve in closed position with its port 15connecting the cylinder pipe 13 with the exhaust outlet 16 so that thespring 12 may shift the piston to the rear end of the cylinder. Uponopening movement of the valve, the port 15 will connect the cylinderpipe 13 with the supply pipe 14 for flow of air to the cylinder foroutward shift of the piston.

As shown on Figures 1 and 2, a switch mounting plate 11 is located infront of the supporting block II on the table I0 and this plate has thewall 18 extending rearwardly therefrom and secured to the side of theblock. As shown, the wall 18 has the extended slotfil19 for receiving ascrew 88 which threads into the block so that the wall may be adjustedfor location of the switch plate 11 to the desired position in front ofthe block. The plate 11 supports a switch 8| which may be amicro-switch, and this switch is normally open but is to be closed bythe bag or bag container striking the micro-switch 8| after the mouth ofa bag to be sealed is placed in sealing position in front of the sealingboss 42 when the sealing jaw bar 5| is in open position.

Referring to Figure 2, the valve V and various circuit controls aremounted on a panel board 82. These controls include a main switch 83, atiming or limit switch structure 84, an emergency or safety switch 85, asolenoid 86, and a manual switch 81 for the heater circuit. The mainswitch 83 and the heater switch 81 may be located within the switch box88 on the panel board. As shown on Figures 2 and 4, the heating coilcircuit includes a thermostat switch 89 which is located within theheater structure adjacent to the heater coils 43. Current flow isreceived from a suitable current supply circuit 98. The supply conductor9| extends to the main switch 83 from which the conductor 92 extends toone terminal of the switch whose other terminal is connected by aconductor 93 through the manual switch 81 with the conductor 94extending to one terminal of the thermostat switch 89 whose otherterminal 95 is connected with one terminal of the heating coil assembly.The other terminal of the heating coil assembly is connected by aconductor 96 with the supply conductor 91 extending from the supplycircuit 90. The conductor 93 coming out of the safety switch 85 isonnected by conductor 98 with one terminal of the timing switchstructure 84 whose other terminal is connected by conductor 99 with oneterminal of the winding of the solenoid 88 whose other terminal isconnected by conductor 00 with one terminal of the microswitch 8| whoseother terminal connects with the conductor 91 extending from the supplycircuit 90. The armature of the solenoid 86 connects with the valvelever NH. The micro-switch and the safety switch 85 are normally open,and the valve V is normally in exhaust position.

On Figure 1 a package P is shown which includes a bag B which is to besealed. The package shown comprises a rectangular container or 5 box I02which receives the goods to be protected; This box with the goodstherein is inserted into the bag B with its open end against the bottomof the bag, and the outer box I03 is then slipped up around the bottomportion of the bag to receive the box I 02; The box contents are nowentirely within the bag and the cover I08 forms a protection coveringfor the bottom portion of the bag.

To put the machine in service condition. the heater circuit is closed byclosing the main switch 88 and the manual switch 81 and setting thesafety switch 85 to on," the thermostat switch 89 being already closedas the heater frame is cold. Current will now flow through the heatercoils for heating of the heater head M and the heater boss 42 thereon,the thermostat switch functioning to open the heater circuit to preventabnormal heating of the heating boss.

The machine is now ready for operation to seal the package P. Thepackage is placed on the table I in front of the micro-switch 8| butwithout engaging the switch. The mouth of the bag is then closed tobring the mouth walls or lips I04 and I05 into engagement, and thismouth end of the bag is brought into position in front of the heatingboss 42, the jaw bar 5I being still in open position. The package isthen shifted rearwardly against the button of the microswitch 8| toclose this switch for the sealing operation. Upon closure of themicro-switch the circuit through the timing switch structure 84 and thevalve solenoid will be closed and the valve V will be operated by thesolenoid to bring its port I5 into position for connection of the airsupply pipe I4 with the cylinder pipe I3, and the air flow into thecylinder 50 will then move the piston 5i and the connecting rod 62outwardly against the resistance of the spring 12 for downswing of thejaw bar 5I to bring the face plate 58 of the blade structure 55 againstthe closed mouth of the bag to clamp the mouth walls I04 and I05 betweenthe face plate and the face of the heater boss 42, the bag closing wallsbeing then heated along a narrow zone for softening or melt- I04, I00 atthe bag mouth below the heating and sealing zone during the sealingoperation to prevent running down along the bag below the sealing zoneof melted sealing substance, and the strip will also function to confinethe sealing heat to the heater head .4I and the boss 42. After a sealingoperation the package is withdrawn from the machine, the micro-switch 8|then opening ready for the next sealing operation,

The machine is adjustable for sealing of various sizes and shapes ofpackages. The micro-switch I8 is adjustable on the support block II, andthe carrier head I! is vertically adjustable in the frame I4 byoperation of the nut structure 2|. Furthermore, the arm 30 may beadjusted axially in the head I1. Thus packages of different widths andheights may be readily sealed by the machine. The various currentconductors and the air piping are of sufficient length and flexible toreadily permit the adjustment of the machines for different types ofpackages.

We claim as our invention:

1. A sealing machine for sealing the mouth of a bag forming part of apackage whose contents are to be protected by the bag, comprising aheater structure having a heating head presenting a comparatively longand narrow heating surface, a pressure applying structure presenting apressure surface for cooperation with said heating surface, a'supportfor said pressure applying structure, means tending to move said supportto hold said pressure applying structure away from said heating surfaceto permit the mouth of the bag to be aligned between said surfaces readyfor the sealing operation, power means effective when energized to movesaid sup port to carry said pressure applying structure for cooperationwith said heater structure, electrical ing of the sealing substance inthe bag material and pressure sealing together of the bag walls or whichwas set for a predetermined time period of closure of the sealingcircuit, will at the end of such period open the sealing circuit fordeenergizing of the solenoid 85 and return of the valve V to shut ofithe air flow to the cylinder and to connect the cylinder with theexhaust outlet I6 of the valve. Return of the solenoid to valve shut-offposition may be assisted by a spring I06. As the air is being exhaustedfrom the cylinder, the spring I2 will quickly shift the piston and theconnecting rod for upswing of the jaw bar 5|. Thus, for each setting ofthe timing switch structure 84, all the bags sealed by the machine willbe subjected to the same heating and sealing pressure for the samelength of time. Should the automatic controls fail to. function at anytime, the operator need only to press the off button of the safetyswitch 85 for immediate disconnection of the electrical circuits andsetting the valve into exhaust position.

A strip I01 of heat resistant and insulating material is preferablyapplied at the underside of the heating head 4| the strip being securedin a recess I08 in the front end of the wall 31, with its front edgeprojecting a slight distance forwardly of the face of the heating boss42. The purpose of this strip is to clamp the walls control means forsaid power means, an electrical circuit for said electrical controlmeans, a normally open switch for said circuit positioned to be closedby the application thereto of the package after the mouth of the bag forsaid package is aligned in front of said heating surface, closure ofsaid electrical circuit causing energization of said power means wherebythe mouth of the bag will be clamped between said pressure surface andsaid heating surface for heating and pressure sealing thereof, andelectrical timing means included in said circuit to function after apredetermined time interval to open said circuit for release of saidpower means from said electrical controlmeans for withdrawal of saidpressure applying structure from said heating element whereby each bagto be sealed will be subjected for the same length of time to theheating and pressure sealing operation.

2. A sealing machine for sealing the mouth of a bag forming part of apackage whose contents are to be protected by the bag, comprising aheater structure having a, heating head presenting a comparatively longand narrow heating surface; a pressur applying structure presenting apressure surface for cooperation with said heating surface,"

circuit for said electrical control means, a normally open switchpositioned to be closed by application thereto of the package after themouth of the sealing bag for th package has been aligned in front ofsaid heating surface, closure of said switch closing said circuit foroperation of said electrical control means to set said valve forenergizing of said pneumatic power means to move said pressure applyingstructure for clamping engagement between its pressure surface and saidheating surface of the mouth of the bag for sealing thereof, and timingmeans included in said circuit for controlling said electrical controlmeans for setting of said valve for release of said support from saidpower means and movement thereof away from th heater structure.

3. In a sealing machine for the purpose described, a package supportingtable, a guide standard thereon, a head supported on said standard, anarm extending from said head over the table, a heater structure mountedon the outer end of said arm and presenting a comparatively long andnarrow heating surface, a comparatively long and narrow pressureapplying structure for cooperating with said heater struc ture, powermeans mounted on said arm for controlling the movement of said pressureapplying structure whereby th mouth of a package sealing bag aligned infront of said heating surface will be engaged by said pressure applyingstructure for clamping therebetween and said heating surface for heatingand pressure sealing thereof, and means for controlling the operation ofsaid power means, screw means for vertically adjusting said head on saidstandard, and said arm being axially adjustable in said head wherebysaid machine may be adjusted for the accommodation of various sizes andshapes of packages on said table, and means for securing said arm inadjusted position.

4. In a sealing machine for the purpose described, a, heater structurepresenting a comparatively long and narrow heating surface, a jaw memberhaving a slot, acomparatively long and narrow pressure applyingstructure comprising a channel shaped backing bar secured in said slotand a rubber-like strip seated in said channel bar and having acomparatively rigid facing strip secured to its outer side forcooperation with said heating surface, power means for moving said jawmember to carry said pressure applying structure into the sealing fieldin front of said heating surface, whereby the mouth of a bag to besealed 8 aligned in front of said heating surface will be clampedbetween said facing strip and said heating surface for sealing thereof,and control means for said power means.

5. In a sealing machine for the purpose-described, a heater framepresenting a heating head terminating in a comparatively long and narrowheating surface, an electrical heating element in said heater frameadjacent to said heating head, a strip of heat insulating and resistantmaterial on said heater frame below said heating head having its forwardedge terminating a short distance in advance of said heating surface, ajaw member, a comparatively long and narrow pressure applying structurecarried by said jaw member and comprising a channel shape backing barand a strip of rubber-like material seated therein and having a facingsecured to its outer side for cooperation with said heating surface,power means for moving said jaw member to carry said pressure applyingstructure for clamping of the mouth of a bag between said facing plateand said heating surface forsealing thereof, and control means for saidpower means.

6. A sealing machine comprising a heater frame, a jaw member having apressure surface swingable toward and away from said frame, fluidpressure means for swinging said jaw member toward said heater frame,spring means for swinging said jaw member away from said frame, a valvefor controlling fluid flow to and from said fluid pressur means, andactuating means for said valve controlled by the work to be heat sealedfor operating said valve.

JOHN N. VAN EPPS. JOHN W. KRAUS. FRANK MAGYAR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,114,624 Bergstein Apr. 19, 19382,351,058 Marks June 13, 1944 2,140,117 Salfisberg Dec. 13, 19382,340,510 Corley et al Feb. 1, 1944 2,000,461 Batterman May '7, 19352,175,031 Salfisberg Oct. 3, 1939 2,133,716 Reitzes Oct. 18, 19382,166,761 Kohl July 18, 1939 639,262 Mills et al Dec. 19, 1899

